1. Field of the Invention
The present invention relates generally to a structure of a semiconductor device and a method of manufacturing the same, and more particularly to a semiconductor device including a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) having a Fin channel and a method of manufacturing the same.
2. Description of the Related Art
There has been proposed a Fin-type MOSFET (Fin-FET) which is designed to maintain a current driving ability in a MOSFET with a fine structure. The Fin-FET is a multi-gate MOSFET with a three-dimensional structure, which can be fabricated only from an upward direction of a substrate of the Fin-FET.
The Fin-FET has a projection-shaped semiconductor layer (Fin) on the substrate, and both side surfaces of the Fin are used as channel regions. Suppression of an off-leak current that flows through the Fin, that is, punch-through, is a very important task in order to prevent degradation in cut-off characteristics. Related techniques on the Fin-FET have already been disclosed (see, for instance, Masaki Kondo et al., “A FinFET Design Based on Three-Dimensional Process and Device Simulations”, Toshiba Corporation, IEEE, 2003).